Method for producing a moulded body and device

Abstract

A method for producing a molded body is proposed, comprising: applying a layer of particles and applying a binder and curing a molded body; and a device for producing a metallic or ceramic molded body, having a storage volume, which is configured for receiving a suspension of metallic or ceramic particles that are dispersed in a suspension fluid, a layer-forming application device, which is configured for removing an amount of suspension repeatedly from the storage volume and transferring it into a working volume and applying it there as a layer, a dehumidifying device, which is configured for dehumidifying the applied layer in the working volume, a binder application device, which is configured for applying a binder locally to the dehumidified layer in accordance with a layer model of the molded body to be produced, in such a way that particles in the dehumidified layer are adhesively bonded locally to one another and optionally in addition to particles of at least one layer lying under the dehumidified layer, and a demolding device, which is configured for demolding the molded body by detaching binder-free residual material from the particles bonded to another with the aid of the binder; and also a rapid prototyping method, comprising: producing a green body and sintering the green body.

What is claimed is: 
     
       1. A method for producing a molded article comprising:
 applying a layer of particles and applying a binder for forming a shaped body, and curing the shaped body 
 wherein the method comprises the following steps of:
 i. forming a moulded body from a metallic or ceramic material by carrying out the following steps repeatedly:
 a. applying a layer of a suspension of metallic or ceramic particles that have been dispersed in a suspension fluid, in a working volume; and 
 b. dehumidifying the applied layer in the working volume and local application to the dehumidified layer and curing of a binding agent in accordance with a layer model of the moulded body to be produced, in such manner that particles in the dehumidified layer are adhesively bonded locally to each other and optionally also to particles in at least one layer below the dehumidified layer; and 
 
 ii. demoulding the moulded body by detaching binder-free residual material from the particles bonded to each other with the aid of the binder to form a green body; 
 
 wherein the layer is generated using a hollow doctor blade. 
 
     
     
       2. The method according to  claim 1 , wherein the binder is applied locally in a printing device. 
     
     
       3. The method according to  claim 1 , wherein the applied layer is heated during dehumidification. 
     
     
       4. The method according to  claim 1 , wherein the moulded body is produced as a porous moulded body. 
     
     
       5. The method according to  claim 1 , wherein curing the binder involves one or more steps from the following group of steps: air-drying, supplying heat and irradiation with UV light. 
     
     
       6. The method according to  claim 1 , wherein demoulding is carried out at least partly in a liquid bath. 
     
     
       7. The method according to  claim 1 , wherein in that the moulded body is produced with a density of at least 60% v/v. 
     
     
       8. The method according to  claim 1 , wherein a green sheet is formed during application of the layer by the application of a suspension of ceramic particles. 
     
     
       9. The method according to  claim 1 , wherein the binder includes an organic binder which is not soluble in water and/or not soluble in organic solvents after curing. 
     
     
       10. The method according to  claim 1 , wherein the binder includes an inorganic binder. 
     
     
       11. The method according to  claim 1 , wherein the moulded body is sintered after demoulding. 
     
     
       12. The method according to  claim 1 , wherein the method includes locally applying corresponding to the layer model of the moulded body to be produced a liquid binder that alters the solubility of the green body, in such manner that the solubility of the moulded body is homogeneous and is different from that of the surrounding particulate material. 
     
     
       13. The method of  claim 1 , wherein
 (a) the step of applying a layer includes applying a layer of a suspension containing a binder that is laser-curable and/or laser-crosslinkable; 
 (b) the step of curing includes curing and/or crosslinking the binder by local laser exposure; and optionally repeating steps (a) and (b), wherein an additional layer is applied to a cured and/or crosslinked layer; 
 (c) and the method includes washing out and/or dissolving components that have not been cured and/or crosslinked in a liquid medium to obtain a green body. 
 
     
     
       14. The method of  claim 1 , wherein the method includes moving the doctor blade with a manipulator. 
     
     
       15. A method for producing a molded article comprising the steps of:
 applying a layer of particles and applying a binder for forming a shaped body, and curing the shaped body, 
 wherein
 (a) the step of applying a layer includes applying a layer of a suspension containing a binder that is laser-curable and/or laser-crosslinkable; 
 (b) the step of curing includes curing and/or crosslinking the binder by local laser exposure; and optionally repeating steps (a) and (b), wherein an additional layer is applied to a cured and/or crosslinked layer; 
 (c) and the method includes washing out and/or dissolving components that have not been cured and/or crosslinked in a liquid medium to obtain a green body, wherein the layer is generated using a hollow doctor blade. 
 
 
     
     
       16. The method according to  claim 15 , wherein the layer is generated utilizing the suspension in which the binder is contained, wherein a solid content of the suspension is selected from the group consisting of a polymer, a metal, a ceramic material and a mixture containing at least one polymer, one metal or one ceramic material. 
     
     
       17. The method according to  claim 15 , wherein the generation of the layer involves at least partial penetration of a binder into a dehumidified layer of a suspension that does not contain any binder. 
     
     
       18. The method according to  claim 17 , wherein the penetration of the binder is effected by spraying the dehumidified layer with the binder and/or by immersing the dehumidified layer in the binder or in a liquid containing the binder. 
     
     
       19. The method according to  claim 15 ,
 wherein the cured and/or crosslinked binder is not soluble in the liquid medium; and 
 wherein the medium comprises water and/or an organic solvent; and 
 wherein the organic solvent is selected from the group consisting of acetone, cyclohexane, dioxane, n-hexane, n-octane, toluene, trichloroethanol, dimethyl ethyl ketone, isopropanol, ethyl alcohol, methyl ethyl ketone, and mixtures obtained therefrom. 
 
     
     
       20. The method according to  claim 16 ,
 wherein a density of the green body is at least 60% of the average material density of a solid portion of the suspension, when the density of the green body is defined as the quotient from a mass of the green body and a volume calculated on the basis of exterior contours of the green body; and 
 wherein the dimensions of layer correspond to the dimension information of a layer model that is constructed one layer at a time. 
 
     
     
       21. A device for producing a metallic or ceramic moulded body, comprising:
 i. a storage volume that is configured to accommodate a suspension of metallic or ceramic particles that are dispersed in a suspension fluid, 
 ii. a layer-forming application device including a hollow doctor blade for repeatedly applying the suspension from the storage volume to a working volume; and 
 iii. a binding agent application device configured to apply a binder locally to the layer in accordance with a layer model of the moulded body to be produced after dehumidifying the layers, so that particles in the dehumidified layer are adhesively bonded locally to one another. 
 
     
     
       22. The device of  claim 21 ,
 wherein the layer-forming application device is configured to repeatedly remove a quantity of suspension from the storage volume as a layer, 
 wherein the device includes a dehumidifier that is configured to dehumidify the applied layer in the working volume, and 
 a demoulding device that is configured to demould the moulded body by detaching the binder-free residual material from the particles bonded to each other with the aid of the binder.